This invention relates to a hydraulic control valve device for use in a system which controls vehicle slips or vehicle behavior, such as an anti-lock braking system (hereinafter ABS) or a traction control system (hereinafter TCS) a vehicle behavior control. More specifically, this invention relates to a hydraulic control valve device which uses an open channel during normal braking operation and switches to a throttled channel during hydraulic pressure control.
A brake device which prevents wheel locking by electronically controlling brake hydraulic pressure when applying immediate braking or immediately starting is publicly known. In this type of device, a metal sound, i.e., noise, vibration, harshness, (NVH) is created while switching the electromagnetic normally open valve (hydraulic control valve device hereinafter) to the closed position. In order to prevent NVH, a switching valve, operated by hydraulic pressure difference, is recommended to be installed at the upstream side of an inlet valve located in a main hydraulic braking line.
Although the above-mentioned preventive measure may reduce NVH to a certain degree, NVH and vibration still occur leaving room for improvement.